The forthcoming Christmas special of 'Doctor Who' is set to be quite the ride for viewers, as not only will we get our first glimpse of the eagerly anticipated Thirteenth Doctor, but will also get to see one final appearance from one of the Doctor's previous companions.

Jenna Coleman at The Fashion AwardsJenna Coleman at The Fashion Awards

There are all sorts of rumours flying about regarding the actor or actress who will embody the next incarnation of the Doctor, but to add more excitement to the mix, we'll get to greet good old Jenna Coleman once again as Clara Oswald who we thought had made her last appearance in series nine.

'Jenna Coleman has agreed to film something new as Clara', a source told The Mirror. 'It's become a tradition now for the companions to reappear as the Doctor regenerates and Jenna isn't letting the side down. It'll help to give Peter the send-off he deserves after three years.'

Indeed, we'll finally bid farewell to Peter Capaldi and make way for a new face. Needless to say, they are keeping that well under wraps. Many are speculating that a woman will take the place of the Timelord, after the series followed the transition between the Master (John Simm) and Missy (Michelle Gomez). It certainly would make sense, given that Bill Potts (Pearl Mackie) seemed to make her last appearance at the weekend with 'The Doctor Falls' from series ten, and yet we still have his male sub-companion hanging around - Nardole (Matt Lucas). 

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Whatever happens this Christmas, we'll be pleased to see Clara once again. It's not the first time an old companion has returned; Rose Tyler (Billie Piper) ended her reign after series one and two, but returned for three episodes in 2008's fourth series and again in two specials from 2010 and 2013. Even Sarah Jane, who was in the original series with the Third and Fourth Doctor from 1973 to 1976, reappeared in 2005 alongside the Tenth Doctor (David Tennant).